First definitive observations of meteor shower particles using a high-power large-aperture radar
First definitive observations of meteor shower particles using a high-power large-aperture radar
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使用高功率大孔径雷达首次对流星雨粒子进行明确观测
DOI：
10.1016/j.icarus.2007.09.021
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发表时间：
2008
期刊：
影响因子：
3.2
通讯作者：
F. Galindo
中科院分区：
文献类型：
--
作者：
J. Chau;F. Galindo
我们提出了第一个明确的观测流星雨活动的流星头回波检测的高功率大孔径雷达（HPLAR）。这种观测是在希卡马卡甚高频雷达上进行的，利用其干涉测量能力，可以区分流星雨的回波和更频繁出现的零星流星。到目前为止，HPLARS还无法区分流星雨和更常见的零星流星。在这项工作中，我们已经能够检测和表征η-宝瓶座流星雨（ETA）以及英仙座流星雨（PER）阵雨。由于更有利的几何形状，ETA的簇射活动比PER簇射更明显。也就是说，PER流星来自低仰角，由于地球-大气-雷达仪器的组合，经历了更多的过滤。在这两种情况下，测量到的阵雨回波的平均速度和它们的预期速度之间有很好的一致性，在1 km s−1的几分之一之内。除了与预期的视觉结果很好的一致性外，HPLARS还观察到了各种颗粒大小和质量的流星，而不是通过任何其他技术观察到的。考虑到不同的观测量，与光学观测相比，Jicamarca观测到的ETA流星要多1000倍以上。我们的研究结果表明，Jicamarca和其他HPLARs能够检测到流星雨的回波，但没有干涉测量能力，这样的人口是很难确定只是从他们的速度分布，特别是如果他们的速度分布预计将类似于更占主导地位的零星流星分布。
We present the first clear observations of meteor shower activity from meteor-head echoes detected by a high-power large-aperture radar (HPLAR). Such observations have been performed at the Jicamarca VHF radar using its interferometric capabilities allowing the discrimination of meteor shower echoes from the much more frequent sporadic meteors. Until now, HPLARs were unable to distinguish meteor shower from the much more common sporadic meteor ones. In this work we have been able to detect and characterize the η-Aquariids (ETA) as well as the Perseids (PER) showers. The shower activity is more conspicuous for the ETA than for the PER shower due to the more favorable geometry. Namely, PER meteors come from low elevation angles, experiencing more filtering due to the combined Earth–atmosphere–radar instrument. In both cases, there is an excellent agreement between the measured mean velocity of the shower echoes and their expected velocity, within a fraction of 1 km s−1. Besides the good agreement with expected visual results, HPLARs observe meteors with a variety of particles sizes and masses, not observed by any other technique. Taking into account the different viewing volumes, compare to optical observations Jicamarca observes more than 1000 times more ETA meteors. Our results indicate that Jicamarca and other HPLARs are able to detect the echoes from meteor showers, but without interferometric capabilities such populations are difficult to identify just from their velocity distributions, particularly if their velocity distributions are expected to be similar to the more dominant distributions of sporadic meteors.